Method of making wire brushes



May 31, 1949. J. F. CUNNINGHAM, JR 2,472,003

METHOD OF MAKING W-IRE BRUSHES 2 Sheets-Sheet 1 Filed May 10, 1945 INVENTOR wm f I WITNESSES: Q1/ 344. is. 06191;,

-A.; ATTORNEYS 4 y 1949- .J. F. CUNNINGHAM, JR 2,472,003

METHOD OF MAKING WIRE BRUSHES v Filed May 10, 1945 I 2 Sheets-Sheet 2 INVENTOR AL. ATTORNEYJ'.

Patented May 31, 1949 METHOD OF MAKING WIRE BRUSHES John F. Cunningham, J r., Greensburg, Pa., assignor to Elliott Company, Jeannette, Pa., a corporation of Pennsylvania Application May 10, 1945, Serial No. 592,988

6 Claims.

This invention relates to solid packed wire bristle brushes and to a method of makin them.

It is among the objects of this invention to provide a brush in which a maximum number of wire bristles are packed in a given area, in which the bristles are Welded together at their inner ends into a solid mass, in which the bristles are prevented from bending at the weld, and which includes an inexpensive and easily applied clamp for the welded ends of the bristles. Another object is to provide a method of makin such a brush which is simple, rapid, and inexpensive.

In accordance with this invention a solid pack of wire bristles has all of the bristles welded together at one end. A clamp, for mounting the brush in a suitable holder, is mounted on the welded end of the pack along which it extends inwardly along the bristles with its inner edge tightly engaging the bundle so that flexing of the bristles can not occur at the weld where the bristles have been weakened, but must occur at a distance therefrom. The clamp may be welded to the welded ends of the bristles, and in such a case it preferably is formed from two clips the end portions of which project away from the bundle with their inner surfaces welded together. In another form the clamp is made in one piece and has a channel-shape body receiving the welded end of the bundle of bristles. The ends of the clamp project beyond the edges of the bundle with the opposite side wall of each end portion pressed together and welded. If desired, the clamp may be formed from a plastic molded on one end of the pack of bristles.

Preferably, my brushes are made by clamping along compact bundle of wires at a pair of closely spaced points, and then applying a charge of electricity to the wires between the clamped points to burn the wire apart and simultaneously to weld together the burned ends of the wires in each of the two bundles thus formed. By severing the wires of a Welded bundle at a predetermined distance from their welded ends, a solid pack of bristles welded together at one end is formed. The bristles are held together securely between their ends by means of a clamp so that bending of the bristles can not occur between the inner edge of the clamp and the weld. Preferably, these clamps are mounted on the bundle of wires before the latter are burned apart, and suiiicient current is used to weld the bristles to the clamps as well as to one another. If the bristles are not welded to the clamp at the time the wires are burned apart, the operation may be performed later as a separate step. It is preferred to apply the clamps to the bundle of wires in the form of pairs of cooperating clips which are welded together at their ends before the current is applied that burns the wires apart.

The preferred embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 is a diagrammatic view of apparatus for producing clamped bundles of wire; Fig. 2 shows a short bundle about to be cut in two; Fig. 3 shows two bundles formed from the preceding cutting operation; Fig. 4 shows the bristles of a brush being welded by an arc welder to their clamp; Fig. 5 is a longitudinal section through Fig. 1; Fig. 6 is an enlarged cross section of the clip-applying device; Fig. 'l is a perspective view of a finished brush; Fig. 8 is a side view of a brush holder with a plurality of my brushes mounted therein; Fig. 9 is a perspective view of the parts required to make a pair of modified brushes; Fig. 10 is an end view of one of the modified brushes; and Fig. 11 is a cross section taken on the line XIXI of Fig. 10. s

In making these brushes a long, compact bundle of wires is formed in any suitable manner. One Way of doing this continuously is illustrated more or less diagrammatically in Figs. 1 and 5 of the drawings, wherein wires I from hundreds of spools 2 are led through a compacting opening 3 in a guide plate 4. This opening is the size and shape of the bundle of wires that is to be formed, preferably wide and flat, and enough wires extend through it to compel them to press tightly together and to completely fill the opening as a solid pack. For example, a bundle has been produced in accordance with this invention which is about one inch wide and inch thick, from about 1700 wires.

A short distance in front of the plate the compact bundle of wires passes through a clip-applying and weldin device formed from spaced cooperating blocks 6 on opposite sides of the wire bundle. The blocks are movable toward and away from each other, and both are provided in their inner walls with a pair of closely spaced recesses for snugly receiving preformed metal clips 1 that are applied to the wire bundle when the blocks are pressed together, as shown in Fig. 6. The recesses in each block are only about inch apart. The blocks are connected by wires 8 to a transformer 9 for supplying welding current to the clips disposed in the recesses. When the blocks with the clips therein close on the temporarily stationary bundle of wires, the clips are pressed tightly around the bundle with their inwardly offset end portions projecting beyond the opposite edges of the bundle. The inner surfaces of these end portions of each clip engage the end portions of the adjoining clip and are spot welded thereto by the current from transformer 9 to form a clamp which tightly engages the bundle of wires and holds it in the desired cross-sectional shape.

The blocks 6 then Fare separated, the bundle is fed forward again adistance roughly equivalent to twice the length of the bristles that are to be contained in the finished brushes, and another set of clips are appliedto the-bundleby blocks 6. Consequently, the bundle of wires leaving the clip-applying device has applied'thereto closely spaced pairs of clamps "dispose'dat-predetermined intervals along its length. Any suitable means may be used to feed thebundleof wires forward intermittently.

Disposed at a location in front of the clipapplying device is apparatus H for electric resist'ance Welding. Thisapparatus is connected "to "the i pair of closely spaced 'clamps nearest to the front end of the continuous bundle of wires. The charge of-electricity thus supplied to the clamps 'flows' through .the short length of Wires "between them and instantly burns the wires "apart like a fuse and thereby produces a short bun'dle l2of-wires' in addition to the long bundle 'fromwhich the shortbundle'was separated. At "the sa'me time the'rnelted ends of the wiresin each of these bundles fuse I together into a solid mass. Each'short Wire bundle 42 formed by-this operation therefore'hast a clamp mounted on each of its ends. It is'preferred to usesufii'cient cur- :rent to' cause the Welded-endsof the wires simultaneously to weld themselves to the outer end of -the surrounding clamp.

The next operation isto cut theseparated short ibundle-in two-substantiall midway between'its 1 end clamps, in order to form twobrushes. cutting may be donein-any suitable mannensuch as by a shear or by an abrasive cutter l3 driven byanelectric motor Ma's shown inFig. 2. Each -of the two wire brushes-thus formed (Fig. 3)

thereforeincludesa closelypacked or solid bundle of'wire bristles l5 welded together at one end where they also are welded. to a surrounding 1 clamp projecting from oppositeedges ofthepack. the clamp tightly'eri'gageslthe pack of bristles, 'it confines their 'flexing'in use'to the portions thereoiprojecting from the clamp; that is,-they can: not bendati'points-any closer to their welded endsthan'the inner edge'of'the clamp. This is hlghly desirable because the welding-heat weakens the bristles at' their inner GI'ldSpSO that they would break olf'if they were allowed tobend "atthat point.

If,'for anyreason, the' wires are-not welded to -the'clamps-by welding apparatus lI,-such welding can be accomplished later as a separate operation. For eXa-mple,-after the brushes have been formed, the welded-ends oi'th'eir bristles can be --welded to'theouter ends of the clamps by an arc -welder' l"!,-as shown in Fig. 4.

=If desired, the clip-applying device can be -eliminated,'and the electric current of Welder ll scan be applied to the continuous bundle of wires -between temporarily clamped points close together :in order to burn the wires apart'between those :points and simultaneously to weld together the -burnedends of the wires in each of the two 'bundles thus formed. The short bundleseparated from the long bundle of Wires will not have clamps at its opposite ends at this time, but the are -added before thebundle is cut in two to form two This *over one rend ofLthe short bundle :of wires. sides of the clip-then are pressed inwardly against parallel, asshoWn in Fig. 11.

packs of bristles in each of which the bristles are welded together at one end. One of these short bundles of bristles 2B is shown in Fig. 9, which also shows clips or clamps 2| ready to be applied to the welded ends of the bundle. As there illustrated, a desirable type of metal clamp for this purpose is U-shape in cross section and is slipped The the pack to tightly engage the outer bristles, whereby the side walls of the clamp are made The end portions of the clamp projecting beyond the edges of the bundle :are compressed to bring their opposite sidewalls into'engagement (Fig. 10) so that they can be welded-together to keep the clamp from -.sliding lengthwise off the pack of bristles.

The rough side edges of the pack at the welded end help prevent the pack from sliding forward out of the clamp. The Wire bundle with clamps at both ends then-is cut to-form twobrushes.

A plurality of .finished brushes, .likethe ione shown in-F'ig. -7 or in Fig. 10,aaremounted/in a cylindrical holderii-illustrated in Fig. 8, adapted to be connected at one end to a driving motor-(not shown) by whichthe-brush assembly can beretatedin a .tubetoclean deposits from theinner surface thereof.

The brush .holder is provided with a plurality of circumferentially spacedradial slots -26 in which .the brush-clamps -'l are-dis- -p0sed. The projecting ends .ofrthe clampszextend scribed what I now-consider torepresent its-best embodiment. However, I desire. to have itunderstood that, within the scope of the appended claims, the inventionmay. be practiced .otherwise than as specifically illustrated and described.

Iclaim:

1. .In the. methodof making wire bristle brushes, the stepscomprising clamping-along-compact bundle of wires at apair of closely spaced ipoints, applyinga charge of electricity to the wires between said clamped pointstoburnsaid wires apart andsimultaneously to-weld-together the burned endsof the wires in each-of the-two bundles thus formed, and severing .the wires-ofia welded-end bundle at a distance from their welded ends to provide apack of bristles welded to- -gether at one end.

2. The method of making wire .bristle brushes, comprising tightly surrounding a long compact bundle of wires by a pair of closely spaced clamps, connecting a ,great enough charge .or

electricity to said-clamps to burn said wires. apart between the clampsand simultaneously to weld the burned ends of the wiresin each clamptogether and tothe surrounding clamp,iand-severing the wires .on the opposite side.of.each...clamp at a distance therefrom to provide bristles projecting from the clamp.

3. The methodof making wirebristlebrushes,

. comprising tightly surrounding a long compact bundle of wires by a pair of closely spacedclamps,

connecting a charge of-electricitytosaid clamps lto burn' said wires *apartbetweena'the clamps'and simultaneously to weld together the burned ends of the wires in each clamp, severing the wires on the opposite side of each clamp at a distance therefrom to provide bristles projecting from the clamp, and then welding the welded ends of the bristles to the outer end of the clamp.

4. In the method of making wire bristle brushes, the steps comprising feeding a continuous compact bundle of wires forward, periodically clamping the bundle at a pair of closely spaced points and applying a charge of electricity to said wires between said clamped points to burn the wires apart and simultaneously to weld together the burned ends of the Wires in each of the two bundles thus formed, whereby the wires in the forward short bundle have their ends welded together at both ends of the bundle, and then severing said short bundle of wires substantially midway between its ends to provide two packs of brush bristles.

5. In the method of making Wire bristle brushes, the steps comprising feeding a continuous compact bundle of wires forward, periodically clamping the bundle at a pair of closely spaced points and applying a charge of electricity to said wires between said clamped points to burn the wires apart and simultaneously to weld toether the burned ends of the wires in each of the two bundles thus formed, whereby the wires in the forward short bundle have their ends welded together at both ends of the bundle, mounting clamps on both ends of said short bundle, compressing each clamp on the short bundle and securing each end of the clamp together to hold the clamp on the bundle, and then severing said short bundle of wires substantially midway between its ends to provide two packs of brush bristles mounted in clamps.

6. The method of making wire bristle brushes, comprising feeding a continuous compact bundle of wires forward, periodically applying two closely spaced pairs of clips to opposite sides of said,bu ndle, welding together the ends of each pair of clips to form a clamp, then connecting a charge of electricity to said clamps to burn said wires apart between the clamps and simultaneously to weld the burned ends of the wires in each clamp together and to the surrounding clamp, whereby the forward short bundle of wires has a clamp welded on each end, and then severing said short bundle between its end clamps to produce two packs of bristles projecting from clamps.

JOHN F. CUNNINGHAM, JR.

REFERENCES CITED The following references are of record in the of this patent:

UNITED STATES PATENTS Rohweder Sept. 1, 1942 

